• Thursday , 22 August 2019

## 3D Character Modeling With NURBs

The most appropriate technology for modeling most characters is NURBS (Non Rational Uniform B-Splines). Curves models work well because they can be very smooth and organic without much detail in the geometry-something that is a major limitation for Polygonal models. This can be easily demonstrated with a Sphere primitive.

You can see that a sphere, which was made of polygons, must be of much higher detail to achieve the same level. Curves modeling provides you with several options for building character geometry. From the head all the way down to individual toes, NURBS models can work best. your 3D application gives you several options for creating your characters.

In the coming sections, you will see how to use the various modeling technologies to construct different components of a character. of smoothness as the Non Rational Uniform B-Splines sphere. U-Lofts and Ruled Surfaces U-Lofts are created by “draping” a surface over a series of NURBS curves. The surface itself is interpolated across several curves so as to produce a “flowing” look.

This means that you will never see where the cross-sections exist. They act more as framework for the surface to loosely adhere to. U-Lofts work best when you are trying to create a complex shape from a series of similarly shaped curves, such as an arm, for instance. The arm is essentially a circular shape created down a long axis.

You can build incredibly complex surfaces this way. The primary limitation is that the loft cannot split. This means that when you get to the end of the arm, you will need to stop at the palm and then join the fingers.

To work properly, you need to build cross-sections that will make up the overall shape of the arm. This is best achieved by using one shape and then copying it multiple times until you have enough cross-sections to build the object you want. For curve based surfaces to be built from cross-sections, you will also need to attach them so that they are treated as one object. Lastly, you will need to convert the entire set of curves into a NURBS surface. From there, you can use the U-Loft command to loft across the cross-sections to create the object.

Using the U-Loft surfaces, you can easily create smooth, contoured objects through the use of cross-sections. Although a similar result could have been generated using the polygonal Loft object, the curve based equivalent requires less geometric detail and It is much easier to animate.

Source by Daniel Kreimer